$\="\n";

for my $foo (qw/abc foo bar 42 unknown/) {
  eval {goto "_$foo"} or
    do {
      print "default";
      next;
    };
  
 _abc:
  print 'abc';
  next;
  
 _foo: ; _bar:
  print "foo bar";
  next;

 _42:
  print "42";
  next;
 
}

__END__
abc
foo bar
foo bar
42
default